Teleconference terminal equipment and teleconference module

ABSTRACT

A teleconference terminal equipment adapted to construct an AV meeting system as an intended use, comprising a network interface and communications network control unit, a multimedia multiplexing/demultiplexing and interterminal signal control unit which multiplexes and demultiplexes video data and control data contained in a communication frame to be transmitted by the control unit and a communication frame received by the same, respectively, a picture codec which codes and decodes video data, a video input/output interface which connects an external camera to the picture codec, a camera control/external device multiconnector, and a CPU which controls an operation of the external camera through the multiconnector on the basis of control data delivered from the control unit.

This is a continuation of application Ser. No. 07/913,489, filed Jul.15, 1992 now U.S. Pat. No. 5,477,546.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a teleconference system which exchangesspeech, video etc. through a communication circuit in real time.

2. Description of the Prior Art

Heretofore, a video telephone system and a teleconference system havebeen known as systems in each of which speech, video etc. are exchangedthrough a communication circuit in real time.

The video telephone system is chiefly intended for telephoniccommunications between one person and another similar to a conventionaltelephone. On the other hand, the teleconference system is intended forteleconference between a number of people, and it has a construction inwhich importance is attached to meeting functions required for such ateleconference.

A prior-art equipment for the teleconference system is constructed bycombining independent devices such as a display unit, a codec, amicrophone and a console. In some cases, a document camera, anelectronic blackboard and a small-sized computer are further combined inaccordance with functions required for conferences.

There is also a teleconference equipment wherein fundamental devices arehoused in a single rack so as to be movable, thereby dispensing with theneed for an exclusive conference room.

Techniques relevant to these equipments are disclosed in the officialgazettes of Japanese Patent Applications Laid-open No. 9790/1990 and No.22989/1990.

In addition, Japanese Patent Applications relevant to teleconferencesystems filed by the assignee of the present application are PatentApplications Laid-open Nos. 166884/1991 and 120889/1992, and PatentApplications Nos. 406984/1990, 5987/1991, 25991/1991, 34009/1991,174025/1991, 174031/1991 and 174049/1991.

Most of the video telephone systems in the prior art do not have thehigh-degree functions necessary for teleconferences such as theteleconference systems have, because it is presumed that they are onlyused between one person and another. On the contrary, teleconferencesystems in the prior art are inherently endowed with such high-degreefunctions. In consequence, however, they become high in cost and largein size and are not suitable for a simple telephone conversation betweenone person and another.

In general, it is required of a teleconference that many people canwatch a screen at the same time. Therefore, a display unit shoulddesirably be large to some extent. Besides, codecs for processing alarge amount of picture information at high speed have not to date beenreduced in size considerably, and most of them are large in size.

For these reasons, the prior-art equipment for the teleconference systemconstructed by combining such devices is large in scale, and ateleconference room for exclusive use is usually necessitated.Accordingly, the introduction of a teleconference system involves aheavy financial burden. Moreover, when holding the teleconference,conferees must move to the teleconference room which is inconvenient. Inthis regard, even portable teleconference equipment needs many people tomove it on account of its size and weight and cannot be used with ease.

Meanwhile, the display unit which is most common at present is a CRTdisplay device, which is mainly used for displaying the receivedpictures of television broadcasting. Since such a display unit isessentially a versatile device, it can construct a BS (broadcasting bysatellite) receiving system conjointly with a BS receiver moduleconnected thereto and a playback display system for recorded picturesconjointly with a video tape recorder module connected thereto.Therefore, such display units are already installed in many places wherepeople gather, such as living rooms in homes and conference rooms.Herein, the display unit for use in the teleconference system need notbe a special device. Incidentally, this is also true of the videotelephone system wherein speech and pictures are exchanged in one to onecorrespondence.

SUMMARY OF THE INVENTION

In view of the above circumstances, the present invention has for itsobject the provision of a teleconference system which can flexibly copewith all intended uses.

Another object of the present invention is to provide a teleconferencemodule which is a unitary apparatus being small in size and easilyportable and which can realize a teleconference system or a videotelephone system when connected to an existing display unit.

In one aspect of performance of the present invention, there is provideda teleconference terminal equipment for exchanging pictures and speechwith an opposite communicating terminal equipment through acommunication circuit which comprises communication control means fortransmitting and receiving communication frames through a digitalcommunication channel, each communication frame being capable ofcontaining video data, audio data, user data and control data,multiplex/demultiplex means for, respectively, multiplexing anddemultiplexing the video data, audio data, user data and control data ofeach communication frame to be transmitted or received by thecommunication control means, a picture codec which decodes a picturesignal from the video data demultiplexed from within the communicationframe by the multiplex/demultiplex means and then delivers the picturesignal as an output, and which codes an input picture signal to-be-codedinto the video data and then transfers the video data to themultiplex/demultiplex means, a camera which supplies the picture codecwith a picked-up picture signal as the picture signal to-be-coded; adisplay unit which displays a picture indicated by the picture signaldecoded by the picture codec, an audio codec which decodes a speechsignal from the audio data demultiplexed from within the communicationframe by the multiplex/demultiplex means and then delivers the speechsignal as an output, and which codes an input audio signal to-be-codedinto the audio data and then transfers the audio data to themultiplex/demultiplex means, a microphone which supplies the audio codecwith a picked-up speech signal as the speech signal to-be-coded, aloudspeaker which emits speech based on the audio signal decoded by theaudio codec, a video input/output interface which supplies the picturecodec with an external input picture signal as the picture signalto-be-coded, and which delivers the picture signal decoded by thepicture codec, as an external output; a camera control interface whichproduces a camera control signal for controlling the operation of anexternal camera connected outside said teleconference terminal equipmentand a control unit which controls the produced camera control signal ofthe camera control interface on the basis of the control datademultiplexed from within the communication frame by themultiplex/demultiplex means.

In operation, the teleconference terminal equipment and the oppositeequipment can communicate with each other through direct controls, sothat the intended uses of such terminal equipments can be flexibly copedwith.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the general arrangement of ateleconference terminal equipment according to the first embodiment ofthe present invention;

FIG. 2 is a block diagram showing the construction of a picture codecwhich is included in the teleconference terminal equipment of the firstembodiment;

FIG. 3 is a block diagram showing the construction of a PinP (Picture inPicture) processor which is included in the teleconference terminalequipment of the first embodiment;

FIG. 4 is an explanatory diagram showing the aspects of a PinP processwhich is performed in the teleconference terminal equipment of the firstembodiment;

FIG. 5 is a block diagram showing the construction of a G3-FAX (group 3type facsimile) interface which is included in the teleconferenceterminal equipment of the first embodiment;

FIG. 6 is an explanatory diagram showing the construction of a cameracontrol/external device multiconnector which is included in theteleconference terminal equipment of the first embodiment;

FIG. 7 is an explanatory diagram showing the construction of a V11/RS422multiconnector which is included in the teleconference terminalequipment of the first embodiment;

FIGS. 8(a) and 8(b) are a perspective view and a rear view showing theexternal appearances of the teleconference terminal equipment of thefirst embodiment, respectively;

FIG. 9 is a block diagram showing an example of construction of ateleconference system according to the first embodiment of the presentinvention;

FIG. 10 is a block diagram showing another example of construction ofthe teleconference system of the first embodiment;

FIG. 11 is a block diagram showing still another example of constructionof the teleconference system of the first embodiment;

FIG. 12 is a block diagram showing yet another example of constructionof the teleconference system of the first embodiment;

FIG. 13 is a block diagram showing a further example of construction ofthe teleconference system of the first embodiment;

FIG. 14 is an explanatory view showing the construction and servicesituation of a teleconference system according to the second embodimentof the present invention;

FIG. 15 is an exterior view showing the construction of a teleconferencemodule according to the second embodiment of the present invention;

FIGS. 16(a), 16(b) and 16(c) are a front view, a side view and a rearview of the teleconference module of the second embodiment,respectively;

FIGS. 17(a) and 17(b) are a plan view and a bottom view of theteleconference module of the second embodiment, respectively;

FIG. 18 is a block diagram showing the circuit arrangement of theteleconference module of the second embodiment;

FIGS. 19(a), 19(b) and 19(c) are a schematic plan view, a schematic sideview and a schematic front view showing the internal construction of theteleconference module of the second embodiment, respectively;

FIG. 20 is an exploded perspective view showing the state of theassemblage of the teleconference module of the second embodiment;

FIG. 21 is a perspective view showing the external construction of acontrol keyboard according to the second embodiment of the presentinvention;

FIG. 22 is an explanatory view showing the key arrangement of thecontrol keyboard of the second embodiment;

FIGS. 23(a), 23(b) and 23(c) are a front view, a plan view and a bottomview of the control keyboard of the second embodiment, respectively;

FIGS. 24(a), 24(b), 24(c), 24(d), 24(e) and 24(f) show the controlkeyboard of the second embodiment, and are a right side view, a leftside view, a rear view, a schematic sectional view taken along line A-A'in FIG. 23(a), a schematic sectional view taken along line B-B' in FIG.23(b) and a schematic sectional view taken along line C-C' in FIG.23(b), respectively;

FIGS. 25(a) and 25(b) are a block diagram and a schematic diagramshowing the circuit arrangement of the control keyboard of the secondembodiment, respectively;

FIG. 26 is an exterior view showing the construction of a documentphotographing stand according to the second embodiment of the presentinvention;

FIGS. 27(a), 27(b), 27(c) and 27(d) are a front view, a right side view,a plan view and a bottom view of the document photographing stand of thesecond embodiment, respectively;

FIGS. 28(a) and 28(b) are a rear view and a left side view of thedocument photographing stand of the second embodiment, respectively;

FIGS. 29(a) and 29(b) are views for explaining the relationships amongthe dimensions of the constituent parts of the document photographingstand of the second embodiment;

FIGS. 30(a), 30(b) and 30(c) are a front view, a right side view and aplan view showing the folded state of the document photographing standof the second embodiment, respectively;

FIG. 31 is an explanatory view showing the situation of the minor framedisplay of a display unit according to the second embodiment of thepresent invention;

FIG. 32 is an explanatory diagram showing messages which are displayedon the screen of the display unit of the second embodiment; and

FIG. 33 is an explanatory diagram showing graphic user interfaces whichthe teleconference module of the second embodiment offers through thedisplay unit.

PREFERRED EMBODIMENTS OF THE INVENTION

Now, the first embodiment of a teleconference terminal equipmentaccording to the present invention will be described.

FIG. 1 illustrates the block arrangement of the teleconference terminalequipment in this embodiment.

As shown in the figure, the teleconference terminal equipment of thisembodiment comprises a camera 1, an LCD (liquid-crystal display) 2, dialfunction keys 3, a VSW (video switch) 4, a picture codec 5, a telephonecontrol man-machine interface 6, a multipoint conversation control 7, amultimedia multiplexing/demultiplexing and interterminal signal controlunit 8, a network interface and communications network control unit 9, aD/R (driver) 10, a VDT (voltage detector) 11, a audio codec 12, an ASW(audio switch) 13, a hands-free set 14, a handset 15, a G3-FAX interface16, a V11 D/R 17, an RS422 D/R 18, an RS232C D/R 19, a datamultiplexor/demultiplexor 20, a communication interface matching section21, a bus SW (switch) 22, communication ports 23˜25, a control unit 26,peripheral device control interfaces 27˜28, and a no-voltage contact 31.

In addition, as external input/output terminals, the teleconferenceterminal equipment comprises a video I/O interface 110, an audio I/Ointerface 109, a microphone input 108, a G3-FAX modular jack 107, aV11/RS422 multiconnector 106, an RS232C connector 105, a mouse jack 104,a conference console connector 103, and a camera control/external devicemulticonnector 101.

The network interface and communications network control unit 9 isconnected to a digital communications network through the D/R 10, and itperforms the communication controls and communication processing betweenthe teleconference terminal equipment and the network, such asestablishing a communication channel with the opposite communicatingterminal equipment. The multimedia multiplexing/demultiplexing andinterterminal signal control unit 8 performs various controls betweenthe pertinent terminal equipment and the opposite terminal equipment.Besides, this control unit 8 demultiplexes video data, audio data, datato be multiplexed/demultiplexed, control data, etc. from within areceived communication frame into the individual data types, and itmultiplexes such types of data into a transmission communication frame.The video data mentioned above is interface data on the network side ofthe picture codec 5, while the audio data is interface data on thenetwork side of the audio codec 12. The data to bemultiplexed/demultiplexed is interface data with respect to the datamultiplexor/demultiplexor 20. The control data is transferred betweenthe control unit 8 and the control unit 26.

The data multiplexor/demultiplexor 20 further demultiplexes the datademultiplexed from within the received communication frame by themultimedia multiplexing/demultiplexing and interterminal signal controlunit 8, into individual data types in accordance with protocolsstipulated with the opposite communicating terminal equipmentbeforehand.

Specifically, in a case where a frame stipulated in CCITT RecommendationH. 221 is supposed as the communication frame, the multimediamultiplexing/demultiplexing and interterminal signal control unit 8transfers FAS or BAS data within the frame to and from the control unit26, audio data to and from the audio codec 12, video data in, e.g., aframe stipulated in CCITT Recommendation H. 261 to and from the picturecodec 5, and data to-be-multiplexed/demultiplexed to and from the datamultiplexor/demultiplexor 20. Besides, in a case where MLP data iscontained in the frame stipulated in CCITT Recommendation H. 221, it istransferred between the control unit 8 and either the control unit 26 orthe data multiplexor/demultiplexor 20 under the control of the controlunit 26.

Herein, the data multiplexor/demultiplexor 20 demultiplexes the datato-be-demultiplexed into G3-FAX data, computer data, various controldata, etc. in accordance with the protocols stipulated with the oppositecommunicating terminal equipment beforehand, and it delivers thedemultiplexed data items to the G3-FAX modular jack 107, V11/RS422multiconnector 106 and RS232C connector 105. Contrariwise, the datamultiplexor/demultiplexor 20 multiplexes the data to-be-multiplexeddelivered from the G3-FAX modular jack 107, V11/RS422 multiconnector 106and RS232C connector 105 and delivers the multiplexed data items to themultimedia multiplexing/demultiplexing and interterminal signal controlunit 8.

In the case of holding a multipoint teleconference, the multipointconversation control 7 performs the controls required for the start andproceeding of the multipoint teleconference. In contrast, in the case ofholding no multipoint teleconference, the control 7 merely relays data.The VDT 11 is a means for detecting the feed voltage of the pertinentterminal equipment.

The camera 1 picks up a picture, which is presented as a display outputby the LCD 2. The VSW 4 is a video switch which changes-over theconnection of the picture codec 5 with the camera 1, LCD 2 and video I/Ointerface 110. The video input/output of an external video I/O devicecan be connected with the video I/O interface 110.

The picture codec 5 codes a picture signal supplied through the VSW 4,and delivers the coded signal to the multimediamultiplexing/demultiplexing and interterminal signal control unit 8through the multipoint conversation control 7. In addition, the picturecodec 5 decodes the video data demultiplexed from the receivedcommunication frame by the control unit 8 and delivers an output throughthe VSW 4.

The hands-free set 14 is a microphone and a loudspeaker for freeinghands. The G3-FAX interface 16 is a modular jack to which a group 3 typefacsimile can be connected. The audio input/output of an external audioI/O device can be connected to the audio I/O interface 109. An externalmicrophone can be connected to the microphone input 108.

The ASW 13 is an audio switch which changes-over the connection of theaudio codec 12 with the hands-free set 14, handset 15, G3-FAX interface16, audio I/O interface 109 and microphone input 108.

The audio codec 12 codes a speech signal supplied through the ASW 4, anddelivers the coded signal to the multimedia multiplexing/demultiplexingand interterminal signal control unit 8 through the multipointconversation control 7. In addition, the audio codec 12 decodes theaudio data demultiplexed from the received communication frame by thecontrol unit 8 and delivers an output through the ASW 13. Incidentally,the audio codec 12 is connected to the V11/RS422 multiconnector 106through the V11 D/R 17.

The dial function keys 3 are keys for accepting the instructions of auser. The telephone control man-machine interface 6 controls the ASW 13in accordance with a key input from the dial function keys 3, so as toconnect the audio codec 12 with the hands-free set 14, handset 15,G3-FAX interface 16, audio I/O interface 109 and microphone input 108.Besides, the instruction based on the key input is transferred to themultipoint conversation control 7 through the telephone controlman-machine interface 6. In response to this instruction, the multipointconversation control 7 controls the multipoint teleconference.

The G3-FAX interface 16 delivers a signal to-be-transmitted suppliedfrom the G3 FAX (group 3 type facsimile) being an analog FAX connectedto the G3-FAX connector 107, to the audio codec 12 through the ASW 13 inthe case of treating the FAX data as audio data, while it digitizes thesignal to-be-transmitted into a code and delivers the code to the datamultiplexor/demultiplexor 20 in the case of treating the FAX data asdata to-be-multiplexed. Contrariwise, when supplied with received datatoward the G3 FAX by the audio codec 12, the G3-FAX interface 16supplies the G3-FAX modular jack 107 with the received data as it is,and when supplied with received data toward the G3 FAX by the datamultiplexor/demultiplexor 20, the G3-FAX interface 16 decodes thereceived data into an analog signal and delivers the analog signal tothe G3-FAX modular jack 107.

The RS232C connector 105 serves as an RS232C interface, and it is aconnector to which a computer, a word processor or an electronicblackboard can be connected. This RS232C connector 105 is connected tothe control unit 26 or the data multiplexor/demultiplexor 20 through thebus SW 22. The communication interface matching section 21 matches thedata rate of the input/output data of the data multiplexor/demultiplexor20 with that of the input/output data of the RS232C interface 105. Thecommunication ports 24 and 25 are ones which the control unit 26 uses inrelation to the RS232C interface 105.

The V11/RS422 multiconnector 106 serves as a V11 interface and an RS422interface, and it is a connector for connecting an external device. Inthis embodiment, an example in which a conference unit is connected willbe described later.

The multiconnector 106 as the RS422 interface is connected to thecontrol unit 26 through the bus SW 22. The communication port 23 is onewhich the control unit 26 uses in relation to the RS422 interface 106.The multiconnector 106 as the V11 interface is connected to the datamultiplexor/demultiplexor 20.

In compliance with the commands of the control unit 26, the peripheraldevice control interfaces 27 and 28 control the various components inthe teleconference terminal equipment, a mouse connected to the mousejack 104, and a conferential console connected to the conference consoleconnector 103. Also, they control an external device such as externalcamera through the camera control/external device multiconnector 101.

Incidentally, the camera control/external device multiconnector 101transfers the command of the control unit 26 to the external device bymeans of the no-voltage contact 31.

The details of the picture codec 5 will be explained below.

FIG. 2 illustrates the construction of the picture codec 5.

Referring to the figure, the picture codec 5 includes an A/D(analog-to-digital) converter 200, a video coder 201, a still picturecoder 202, a variable-length coder 203, a BCH(Bose-Chaudhuri-Hocquenghem code unit) 204, a PinP (picture-in-picture)processor 205, a video decoder 206, a D/A (digital-to-analog) converter220, a still picture decoder 207, a variable-length decoder 208, a BCH209, and video switches 210, 211, 212, 213, 214 and 215.

Thus, in this embodiment, a still picture and a video are treated, butthe signals thereof are digitized by the single A/D converter 200. Thisis based on the fact that the still picture and the video are notusually transmitted at the same time on account of the limitedtransmission capacity of a communication channel employed in a digitalcommunications network. That is, in order to quickly send the stillpicture of large data quantity to the opposite communicating terminalequipment, the transmission of the video is usually suspended duringthat of the still picture.

Besides, in this embodiment, a still picture and a video which have beenreceived are displayed in a multiplexed state within an identical framethrough the PinP processor 205 to be detailed later, thereby making itmore convenient for use. Moreover, the still and videos are multiplexedinto the identical frame before analogizing the signals of therespective pictures, whereby the single D/A converter 220 suffices forturning the picture data of both the pictures into analog signals.

Next, the operation of the picture codec 5 will be explained.

When supplied with a picture signal through the VSW 4, the A/D converter200 converts the picture signal into a digital signal. Incidentally,although an NTSC signal is assumed as the picture signal to-be-input inthis embodiment, even a signal conforming to another standard such asPAL or RGB can be similarly processed. The digitized picture data istransferred to the PinP processor 205 as the picture data of thepertinent terminal equipment itself.

Under the control of the peripheral device control interface 27, thevideo switches 210 and 211 deliver the digitized picture data to eitherthe video coder 201 or the still picture coder 202, depending uponwhether the input picture signal is for a still picture or a video.

The video coder 201 codes the delivered picture data in accordance withcode rules based on the DCT (discrete cosine transform) stipulated inCCITT Recommendation H. 261. Also, the still picture coder 202 codes thedelivered picture data in accordance with predetermined code rules. Whensupplied with the coded picture data through the video switch 212 fromeither the video coder 201 or the still picture coder 202, thevariable-length coder 203 turns the supplied image data into avariable-length code in accordance with variable-length code rulesstipulated in CCITT Recommendation H. 261. When supplied with thevariable-length code of the image data from the variable-length coder203, the BCH 204 adds BCH data for error correction to the supplied codeinto video data and transfers the video data to the multimediamultiplexing/demultiplexing and interterminal signal control unit 8through the multipoint conversation control 7.

On the other hand, when the BCH 209 is supplied with video data or stillpicture data through the multipoint conversation control 7 from themultimedia multiplexing/demultiplexing and interterminal signal controlunit 8, it checks BCH data for error correction and delivers theerror-corrected video data or still picture data to the variable-lengthdecoder 208. This variable-length decoder 208 decodes the deliveredpicture data in accordance with the variable-length code rulesstipulated in CCITT Recommendation H. 261. The data decoded by thevariable-length decoder 208 is transferred to either the video decoder206 or the still picture decoder 207 through the video switch 215,depending upon whether it is video data or still picture data. Whensupplied with the video data decoded by the variable-length decoder 208,the video decoder 206 decodes it in accordance with the code rulesstipulated in CCITT Recommendation H. 261. Also, when supplied with thestill picture data decoded by the variable-length decoder 208, the stillpicture decoder 207 decodes it in accordance with predetermined coderules such as code rules conforming to the JPEG algorithm of the ISOStandard. The picture data decoded by the video decoder 206 or the stillpicture decoder 207 is transferred as received motion picture data orreceived still picture data to the PinP processor 205 through thecorresponding video switch 213 or 214.

If necessary, the PinP processor 205 performs a PinP process to bedescribed later, by the use of the image data of the pertinent terminalequipment itself transferred from the A/D converter 200 and the imagedata decoded by the video decoder 206 or the still picture decoder 207,and it supplies the D/A converter 220 with the resulting image datawhich has been subjected to the PinP process. The D/A converter 220converts the supplied image data into an analog signal, which isdelivered to the video switch 4.

Then, the picture signal is presented as a display output on the LCD 2or the like in accordance with the operation of the video switch 4.

Next, the details of the PinP processor 205 will be explained.

FIG. 3 illustrates the construction of the PinP processor 205.

Referring to the figure, the PinP processor 205 includes a self-pictureframe memory 301, a still-picture frame memory 302, a motion-pictureframe memory 303, MUX'es (multiplexors) 305, 306 and 307, a major-frameaddress generator 308, a minor-frame address generator 309, a displayframe timing controller 310, and MUX 311.

Next, the PinP process which is performed by the PinP processor 205 willbe explained with reference to FIG. 4.

The "PinP process" is a process for producing a picture-in-picture framefrom a plurality of pictures. That is, it is a process for multiplexingand outputting two picture data in order that different output picturesmay be displayed in a major frame area and a minor frame area asillustrated in FIG. 4.

In this embodiment, the two picture data are selected from among thethree picture data of the self-picture data transferred from the A/Dconverter 200, the received still picture data transferred from thestill picture decoder 207 and the received motion picture datatransferred from the video decoder 206, and they are multiplexed andoutput so as to be displayed in the major and minor frame areas. In thecase where, in this manner, the PinP process is carried out by selectingtwo from the three picture data of the self-picture data, received stillpicture data and received motion picture data, six types ofpicture-in-picture frames can be produced as shown at symbols (a)˜(f) inFIG. 4.

The PinP process of the PinP processor 205 proceeds as stated below.

The self-picture frame memory 301 stores the transferred self-picturedata therein. The still-picture frame memory 302 stores the receivedstill picture data therein. The motion-picture frame memory 303 storesthe received motion picture data therein. The contents of the individualframe memories are sequentially updated.

The major-frame address generator 308 generates addresses for fetchingthe data of a picture to be displayed in the major frame area, indisplay sequence from the frame memory in which the picture data arestored. While the major-frame address generator 308 is generating thedata addresses of the above picture corresponding to the major framearea, the minor-frame address generator 309 generates in parallel withthe address generation of the generator 308, addresses for fetching thedata of a picture to be displayed in the minor frame area, in displaysequence from the frame memory in which the picture data are stored. Onthis occasion, the address generation timings of the minor-frame addressgenerator 309 are controlled by the display timing controller 310.Besides, the picture to be displayed in the minor frame area must bereduced in size as shown in FIG. 4. Therefore, the minor-frame addressgenerator 309 generates skipped addresses in accordance with a reductionrate so as to thin out pixels and then fetch the picture data from theframe memory.

Herein, the addresses generated by the major-frame address generator 308are afforded through the corresponding MUX 305, 306 or 307 to the framememory 301, 302 or 303 in which the picture data to be displayed in themajor frame area are stored. Likewise, the addresses generated by theminor-frame address generator 309 are afforded through the correspondingMUX 305, 306 or 307 to the frame memory 301, 302 or 303 in which thepicture data to be displayed in the minor frame area are stored.

While the minor-frame address generator 309 is generating theaforementioned addresses corresponding to the minor frame area, the MUX311 selects and delivers the picture data fetched from the frame memoryin which the picture data to be displayed in the minor frame area arestored. At any other time, the MUX 311 selects and delivers the picturedata fetched from the frame memory in which the picture data to bedisplayed in the major frame area are stored. A change-over timing forthese operation modes of the MUX 311 is controlled by the display timingcontroller 310.

Incidentally, the frame memories of the PinP processor 205 may well beshared for frame memories which the video coder 201, still picture coder202, video decoder 206 and still picture decoder 207 use for the codingand the decoding.

Next, the details of the G3-FAX interface 16 will be explained.

FIG. 5 illustrates the construction of the G3-FAX interface 16.

Referring to the figure, the interface 16 includes a hybrid 501, a routeSW (switch) 502, a codec 503 for the facsimile, and a FAXsending/receiving call control 504.

When the FAX sending/receiving call control 504 is informed of thereception of G3-FAX data through the peripheral device control interface27 by the control unit 26, it applies a ringer signal to the G3-FAXmodular jack 107. In addition, the FAX sending/receiving call control504 detects the off-hook or on-hook condition of the G3 FAX connectedwith the G3-FAX modular jack 107 and reports the detected condition tothe control unit 26 through the peripheral device control interface 27.Besides, if necessary, the control 504 reports the content of dialing inthe G3 FAX connected with the G3-FAX modular jack 107, to the controlunit 26 through the peripheral device control interface 27.

The hybrid 501 matches the half-duplex interface of the G3-FAX modularjack 107 with the full-duplex interface of the route SW side. In a casewhere the route SW 502 has been informed to the effect of treating theG3-FAX data as data to-be-multiplexed, through the peripheral devicecontrol interface 27 by the control unit 26, it connects the hybrid 501to the audio codec 12. In consequence, the audio codec 12 codes the datasent by the connected G3 FAX and transfers the coded data as audio datato the multimedia multiplexing/demultiplexing and interterminal signalcontrol unit 8 through the multipoint conversation control 7.

On the other hand, in a case where the route SW 502 has been informed tothe effect of treating the G3-FAX data as audio data, through theperipheral device control interface 27 by the control unit 26, itconnects the hybrid 501 to the codec 503 for the FAX. The FAX codec 503codes the sent data of the connected G3 FAX in accordance with the μ/Arules, the ADPCM or the like, and transfers the coded data as datato-be-multiplexed to the multimedia multiplexing/demultiplexing andinterterminal signal control unit 8 through the datamultiplexor/demultiplexor 20.

In this manner, according to this embodiment, the ordinary G3 FAX can beconnected to the teleconference terminal equipment and then used withoutaltering the interface thereof. Furthermore, the G3-FAX data is codedusing the FAX codec 503 and then treated as the data to-be-multiplexed,whereby a telephone conversation is possible with the audio codec 12even during communications with the G3 FAX.

Next, the camera control/external device multiconnector 101 will beexplained.

The teleconference terminal equipment according to this embodiment canhave an external camera, an external monitor, an externalmicrophone/external loudspeaker, etc. connected thereto by the video I/Ointerface 110, the audio I/O interface 109, the microphone input 108,etc.

The camera control/external device multiconnector 101 is a connector forcontrolling the external camera as well as illumination therefor, andthe external microphone among the aforementioned external I/O devices.The control employing this multiconnector 101 is realized in such a waythat the control unit 26 controls the no-voltage contact such as therelay contact 31 in compliance with an instruction from the dialfunction keys 3, an instruction from the console connected to theconference console connector 103, or control data received from theopposite communicating terminal equipment and transferred through themultimedia multiplexing/demultiplexing and interterminal signal controlunit 8. Incidentally, in the case stated before where the framestipulated in CCITT Recommendation H. 221 is presumed as thecommunication frame, the control unit 26 receives the control data inthe form of the FAS, BAS or MLP data from the opposite communicatingterminal equipment and controls the no-voltage contact 31 in accordancewith the received control data.

FIG. 6 illustrates the construction of the camera control/externaldevice multiconnector 101. As shown in the figure, the multiconnector101 contains the signals of spare 613; zooming 612, 611; focusing 610,609; illumination 608; wiper 607; panning 606, 605; tilting 604, 603;camera/microphone changing-over 602, 601; and power source 600.

Using to these signals, the control unit 26 can control the zooming andfocusing of the external camera, and the illumination, a wiper, andpanning and tilting for the external camera, through the cameracontrol/external device multiconnector 101. Also, it can control thechange-over between the camera and the microphone, and the turn-ON/OFFof the power source of any desired external device through themulticonnector 101.

Next, the V11/RS422 multiconnector 106 will be explained.

The V11/RS422 multiconnector 106 is a connector which includes a V11interface and an RS422 interface.

In this embodiment, it is assumed that the conference unit to bedescribed later is connected to the V11/RS422 multiconnector 106.

The RS422 interface within the V11/RS422 multiconnector 106 is connectedwith the control unit 26 through the communication port 23. The controlunit 26 transfers control data to and from the conference unit by theuse of the RS422 interface.

The V11 interface within the V11/RS422 multiconnector 106 is connectedto the data multiplexor/demultiplexor 20 and the audio codec 12. On thebasis of the control of the control unit 26, the datamultiplexor/demultiplexor 20 demultiplexes control data and datato-be-demultiplexed supplied from the multimediamultiplexing/demultiplexing and interterminal signal control unit 8, andit delivers the resulting data to the V11 interface. Contrariwise, thedata multiplexor/demultiplexor 20 multiplexes control data and datato-be-multiplexed delivered from the V11 interface, with FAX data etc.delivered from the G3-FAX interface 16, and it supplies the resultingdata to the multimedia multiplexing/demultiplexing and interterminalsignal control unit 8. Incidentally, in the case of employing theaforementioned H. 221 frame as the communication frame, MPL data can beused as the control data.

Herein, the data which is delivered from the datamultiplexor/demultiplexor 20 to the V11 interface is in the form of theactual burst data demultiplexed and extracted from the communicationframe. Likewise, the data which is delivered from the V11 interface tothe data multiplexor/demultiplexor 20 is burst data having the sametransfer rate as that of data contained in the communication frame.

As stated above, in this embodiment, the data area and control data areaof the communication frame can be opened to the exterior as they are.Accordingly, the V11 interface can freely utilize the predetermined dataarea or control data area contained in the communication frame.

Here, FIG. 7 illustrates the construction of the V11/RS422multiconnector 106.

Referring to the figure, parts 700˜702 constitute the RS422 interface,and parts 703˜710 the V11 interface.

The RS422 interface includes the lines of transmission data 700,reception data 701 and a transfer clock 702. The V11 interface includesthe lines of sending data 703, a sending burst clock 704 synchronizedwith sending burst data, a sending frame sink 705, receiving data 706, areceiving burst clock 707 synchronized with receiving burst data, areceiving flame sink 708, and two basic clocks 709, 710.

Next, the external appearance of the teleconference terminal equipmentaccording to this embodiment are illustrated in FIGS. 8(a) and 8(b).

FIG. 8(a) is a perspective view of the terminal equipment seen obliquelyfrom the front thereof, while FIG. 8(b) is a rear view of the essentialportions thereof showing the arrangement of connectors.

Now, the constructions of teleconference systems each of which employsthe teleconference terminal equipment according to this embodiment willbe described with reference to FIG. 9 thru FIG. 13. In these figures,numeral 1000 indicates the teleconference terminal equipment.

FIG. 9 shows the teleconference system which is suitable for thepersonal telephonic communications between one person and another, FIG.10 shows the teleconference system which is suitable for ateleconference among a small number of people, FIG. 11 shows theteleconference system of simplified type which is used for ateleconference, FIG. 12 shows the teleconference system which issuitable for a regular teleconference, and FIG. 13 shows theteleconference system which is suitable for a larger teleconference.

As seen from the figures, according to the teleconference systems inthis embodiment, a G3 FAX 900, a computer 901 such as a personalcomputer or word processor, a camera 903, a monitor 904, a microphone905, a camera pan-tilter 906, a conference console 907, etc. can beconnected by the video I/O interface 110, audio I/O interface 109,microphone input 108, G3-FAX modular jack 107, V11/RS422 multiconnector106, RS232C connector 105, mouse jack 104, conference console connector103, and camera control/external device multiconnector 101. Thus, theteleconference systems can be flexibly constructed in accordance withintended uses.

In particular, according to the teleconference system in thisembodiment, the external interface based on the digital data of theaudio codec 12 is included in the V11/R422 multiconnector 106 as statedbefore. As shown in FIG. 12, therefore, a digital echo canceler 1200 ofhigh performance can be disposed outside if it is need.

As shown in FIG. 13, a G3 FAX 900, data processing devices 901 such as apersonal computer or word processor and an electronic blackboard, acamera 903, a monitor 904, microphones 905, a camera pan-tilter 906, aconference console 907, etc. may well be connected through a conferenceunit 1300 so as to realize higher degrees of conference functions.

As shown in FIG. 13, the conference unit 1300 includes a videocontroller 1301, an audio controller 1302, a unit controller 1303, avideo processor 1305 and a power source unit 1306. The video controller1301 is connected to the video I/O interface 110 of the teleconferencesystem. The audio controller 1302, unit controller 1303 and videoprocessor 1305 are connected with the V11/RS422 multiconnector 106 ofthe teleconference system through the unshown data interface unitthereof.

The unit controller 1303 controls any of the constituents of theconference unit 1300 in compliance with an instruction from theconference console 907, an instruction from the control unit 26 of theteleconference system as delivered through the RS422 interface, orcontrol data received through the V11 interface from the oppositecommunicating terminal equipment. In addition, the unit controller 1303transfers data received through the V11 interface from the oppositecommunicating terminal equipment, between this V11 interface and thedata processing devices 901 such as the personal computer or wordprocessor and the electronic blackboard.

The video controller 1301 and the still picture processor control thechange-over between, for example, the camera and the monitor which areconnected to the video I/O interface 110 of the teleconference system.The audio controller 1302 controls the change-over between, for example,the microphone and the loudspeaker which are connected to the audiocodec 12 of the teleconference system through the V11 interface. Inaddition, the audio controller 1302 performs an echo canceling processas may be needed. The video processor 1305 performs the control of thecamera pan-tilter 906.

In this manner, according to the teleconference system of thisembodiment, the pertinent terminal equipment can communicate with theconference unit connected to the opposite terminal equipment through themutual direct controls which are performed as needed by the use of thedata area and the control data area opened to the external devices asstated before, and the intended uses of teleconference systems can beflexibly coped with.

Now, the second embodiment of a teleconference system according to thepresent invention will be described.

First, FIG. 14 illustrates the construction of the teleconference systemaccording to this embodiment.

Referring to the figure, the embodiment includes a teleconference module2001 connected to a digital communications network, a control keyboard2002, microphones 2003, a document photographing stand 2004, an.electronic blackboard 2005, a video tape recorder 2006, a display unit2007 and a display unit rack 2008 for housing the display unit 2007therein. In this embodiment, the display unit 2007 shall be explained asbeing a CRT display device which has a built-in loudspeaker.

The illustrated teleconference system is fundamentally configured of theteleconference module 2001, the display unit 2007 connected to theteleconference module 2001, the control keyboard 2002 connected to theteleconference module 2001, and the microphones 2003 connected to theteleconference module 2001 through the control keyboard 2002. Ifnecessary, the system is expanded by connecting the documentphotographing stand 2004, electronic blackboard 2005 and video taperecorder 2006 to the teleconference module 2001. In addition, as will bedescribed later, an external camera, a facsimile machine and asmall-sized computer can be connected to the teleconference module 2001if it is need.

As shown in the figure, the teleconference system of this embodimentfeatures the teleconference module 2001 in the shape of a box. Byconnecting this teleconference module 2001, the control keyboard 2002and the microphones 2003, a teleconference can be held in any of aconference room, a living room, etc. where ordinary display units areinstalled.

The teleconference module 2001 has a built-in camera, and it hasgeometries such that it can be put on the top plate of the rack 2008housing the display unit 2007 therein or put directly on the displayunit 2007. The teleconference module 2001 codes an image picked up overthe top plate of the rack 2008 or over the display unit 2007 by thebuilt-in camera, and transmits the resulting code to the oppositecommunicating side through the connected digital communications network.Also, it decodes the image of the opposite side received through thedigital communications network and then transfers the resulting image tothe display unit 2007.

The teleconference module 2001 will be explained.

FIG. 15 illustrates the external appearance of the teleconference module2001 according to this embodiment.

As shown in the figure, this teleconference module is a box-like onesimilar to common video tape recorders, BS (broadcasting by satellite)tuners, etc. In the illustration, numeral 2101 designates a camerawindow, behind which the built-in camera is mounted. Besides, numeral2102 designates a rotary volume control for adjusting the sensitivity ofeach microphone 2003. Various terminals are mounted on the rear surfaceof the teleconference module 2001.

Next, FIGS. 16(a), 16(b) and 16(c) are a front view, a side view and arear view of the teleconference module 2001, respectively.

As shown in the rear view of FIG. 16(c), the rear surface of theteleconference module 2001 is provided with two video signal inputterminals 2816 and 2825, two video signal output terminals 2817 and2824, an audio signal input terminal 2819, audio signal output terminals2818 and 2823, a modular jack 2820 for a G3 FAX (group 3 typefacsimile), a modular jack 2830 for the digital communications network,an RS232C connector 2821, a connector 2822 for the control keyboard2002, a triple-pole terminal 2311 for connecting a power source cable,and a seesaw switch 2312 being a power switch.

In addition, four supporters 2320 furnished with adjusting mechanismsare provided for adjusting the spacings between the body 2310 and theinstallation plane of the teleconference module 2001 independently ofone another. Thus, the inclination of the body 2310 as well as thecamera included therein can be adjusted.

Further, FIGS. 17(a) and 17(b) are a plan view and a bottom view of theteleconference module 2001, respectively.

Next, the internal construction of the teleconference module 2001 willbe explained.

FIG. 18 shows the internal construction of this teleconference module.

Referring to the figure, numeral 2830 indicates the terminal which is tobe connected to the digital communications network. In this embodiment,the digital communications network is assumed to be the ISDN (integratedservice digital network), and the terminal 2830 to be a modular jackhaving eight pins. Besides, the teleconference module 2001 includes thecamera 2807, a video switch 2806, a video amplifier 2808, a picturecodec 2805, a multimedia multiplexing/demultiplexing and interterminalsignal control unit 2804, a network interface and communications networkcontrol unit 2803, a audio codec 2810, an echo canceler 2811, an audioswitch 2813, an audio amplifier 2812, a FAX interface 2814, a datainterface 2815, a control unit 2802 and a power source 2801.

As mentioned before, the external I/O terminals are the two video signalinput terminals 2816 and 2825, the two video signal output terminals2817 and 2824, the audio signal input terminal 2819, the audio signaloutput terminals 2818 and 2823, the modular jack 2820 for the G3 FAX,the RS232C connector 2821, the connector 2822 for the control keyboard2002, the triple-pole terminal 2311 for connecting the power sourcecable, and the connector 2822 for the control keyboard 2002. Theseconnectors and the above terminal 2803 are arranged on the rear surfaceof the teleconference module 2001 as stated before.

Herein, the network interface and communications network control unit2803 is connected to the ISDN through the connector 2830, and itperforms the communication controls and communication processing betweenthe pertinent teleconference terminal equipment and the network, such asestablishing a communication channel with the opposite communicatingterminal equipment. The multimedia multiplexing/demultiplexing andinterterminal signal control unit 2804 performs various controls betweenthe pertinent terminal equipment and the opposite terminal equipment.Besides, this control unit 2804 demultiplexes video data, audio data,data to be multiplexed/demultiplexed, control data, etc. from within areceived communication frame into the individual data types, and itmultiplexes such types of data into a transmission communication frame.The video data mentioned above is interface data on the network side ofthe picture codec 2805, while the audio data is interface data on thenetwork side of the audio codec 2810. The data to bemultiplexed/demultiplexed is interface data with respect to the datainterface 2815 and the FAX interface 2814. The control data istransferred between the control unit 2804 and the control unit 2802.

The multimedia multiplexing/demultiplexing and interterminal signalcontrol unit 2804 further demultiplexes the data demultiplexed fromwithin the received communication frame, into G3-FAX data, computerdata, various control data, etc. In accordance with protocols stipulatedwith the opposite transmission terminal equipment beforehand, and itdelivers these data to the G3-FAX modular jack 2820 and RS232C connector2821 through the FAX interface 2814 and data interface 2815,respectively.

Conversely, the control unit 2804 accepts data to be transmitted in amultiplexed state, from the G3-FAX modular jack 2820 and RS232Cconnector 2821.

The camera 2807 picks up an image. The video switch 2806 supplies thepicture codec 2805 with an input from the video signal input terminal2816, instead of an input from the camera 2807. Thus, the documentphotographing stand 2004 and the external camera can be connected to thevideo input terminals 2816 and 2825. Accordingly, when the externalcamera for photographing conferees is substituted for the built-incamera 2807, it can be used in the state in which it is housed in thedisplay unit rack 2008.

The picture codec 2805 codes an input picture signal, and delivers theresulting coded signal to the multimedia multiplexing/demultiplexing andinterterminal signal control unit 2804. In addition, it decodes videodata demultiplexed from within a received communication frame by thecontrol unit 2804 and then delivers the resulting decoded data to thevideo signal output terminals 2817 and 2824 through the video amplifier2808. The video signal output terminal 2824 is connected with theexternal video input terminal of the display unit 2007 so as to displaya received picture. On the other hand, the video signal output terminal2817 is connected with the external video input terminal of the videotape recorder 2006 so as to record the contents of the teleconference asand when required.

The audio input and output terminals 2818, 2819 and 2823 can have theaudio input and outputs of external audio devices connected thereto. Theaudio switch 2813 is one by which any of an input from the G3 FAXconnected to the G3-FAX modular jack 2820, an input from a deviceconnected to the audio input interface 2819, and an input from themicrophones 2003 coupled with the control keyboard 2002 connected to theconnector 2822 is transferred to the audio codec 2810 through the echocanceler 2811.

The audio codec 2810 codes an input speech signal, and delivers theresulting coded signal to the multimedia multiplexing/demultiplexing andinterterminal signal control unit 2804. In addition, it decodes audiodata demultiplexed from within a received communication frame by thecontrol unit 2804 and then delivers the resulting decoded data to theaudio output terminals 2818 and 2823 through the echo canceler 2811 aswell as the audio amplifier 2812. The audio output terminal 2818 has theexternal audio input terminal of the video tape recorder 2006 connectedthereto, while the audio output terminal 2823 has the external audioinput terminal of the display unit 2007.

The echo canoelet 2811 performs an echo canceling process between thespeech signal decoded from the audio data and the speech signaldelivered from the audio switch 2813, thereby preventing the occurrenceof howling during communications. Incidentally, the howling may well beprevented by replacing the echo canceler 2811 with an echo suppressorwhich suppresses a selected one of the outputs to the audio amplifier2812 and the input from the audio switch 2813.

The FAX interface 2814 delivers a signal to-be-transmitted supplied fromthe G3 FAX being an analog FAX connected to the G3-FAX modular jack2820, to the audio codec 2810 in the case of treating the FAX data asaudio data, while it digitizes the signal to-be-transmitted into a codeand delivers the code to the multimedia multiplexing/demultiplexing andinterterminal signal control unit 2804 in the case of treating the FAXdata as data to-be-multiplexed. Contrariwise, when supplied withreceived data toward the G3 FAX by the audio codec 2810, the FAXinterface 2814 supplies the G3-FAX modular jack 2820 with the receiveddata as it is, and when supplied with received data toward the G3 FAX bythe multimedia multiplexing/demultiplexing and interterminal signalcontrol unit 2804, the FAX interface 2814 decodes the received data intoan analog signal and delivers the analog signal to the G3-FAX modularjack 2820.

The RS232C connector 2821 serves as an RS232C interface, and it is aconnector to which a computer, a word processor or an electronicblackboard can be connected. This RS232C connector 2821 is connected tothe control unit 2802 or the multimedia multiplexing/demultiplexing andinterterminal signal control unit 2804 through the data interface 2815.

The control unit 2802 performs serial data communications with thecontrol keyboard 2002. Besides, it performs various controls for theconstituents of the teleconference module 2001, for example, the displaycontrol of a menu picture to be described later, on the basis of datatransferred from the multimedia multiplexing/demultiplexing andinterterminal signal control unit 2804 and data transferred from thecontrol keyboard 2002.

The external device interfaces of the teleconference module 2001 will beput in order in Table 1 below:

                  TABLE 1                                                         ______________________________________                                        Items           Contents                                                      ______________________________________                                        External Inputs and Outputs                                                   Video Inputs    2     75 Ω 1 Vp-p                                       Video Outputs   2     Unbalance  RCA pin jacks                                Audio Input     1     Above 40 kΩ                                                                        312 mVrms                                    Audio Outputs   2     Below 2 kΩ                                                                         RCA pin jacks                                FAX Interface   1     Connecting G3 FAX                                       Data Interface  1     RS232C, 1.2˜9.6 kb/s                              ______________________________________                                    

Meanwhile, the picture codec 2805 codes and decodes pictures inconformity with algorithms stipulated in CCITT Standard, H. 261. In thisregard, a picture codec is implemented with two circuit boards eachhaving a size nearly equal to the A5-format in, for example, acommercially-available video telephone set HV-100 (trade name)manufactured by Hitachi, Ltd. In the future, such picture codecs will beincreasingly reduced in size by applying highly-packaged circuittechnology.

FIGS. 19(a), 19(b) and 19(c) are a schematic plan view, a schematic sideview and a schematic front view, respectively, showing the internalstructure of the teleconference module 2001.

As can be seen from the figures, the teleconference module 2001 isconfigured of the camera 2807 and six circuit boards 2601˜2606.

Referring to the figures, numeral 2310 indicates the body of thisteleconference module, and numeral 2320 each supporter furnished withthe adjusting mechanism. The six circuit boards 2601˜2606 are mountedinside the body 2310 as depicted in the figures.

The circuit boards 2601 and 2602 are ones on which the picture codec2805 is installed, and each of which has nearly the same size as theA5-format in the video telephone set HV-100. The circuit board 2603 isone which carries the multimedia multiplexing/demultiplexing andinterterminal signal control unit 2804, network interface andcommunications network control unit 2803, audio codec 2810, echocanceler 2811, FAX interface 2814, data interface 2815, control unit2802, video switch 2806 and video amplifier 2808. The circuit board 2604carries the echo canceler 2811, audio amplifier 2812 and audio switch2813. The circuit boards 2605 and 2606 carry the power source 2801.

In this manner, the picture codec 2805 is configured of the two circuitboards each having the A5-size approximately, whereby the teleconferencemodule 2001 can be realized as the box-shaped module whose size issubstantially equal to the size of, e.g., an ordinary video taperecorder for domestic use. In this embodiment, the size of each of thecircuit boards 2601 and 2602 is 168 mm×184 mm, that of the circuit board2603 is 256 mm×210 mm, that of the circuit board 2604 is 140 mm×260 mm,that of the circuit board 2605 is 156 mm×116 mm, and that of the circuitboard 2606 is 227 mm×88 mm. The body 2310 of the teleconference module2001 is 431 mm wide, 82 mm high and 300 mm deep.

Incidentally, since dedicated LSI's being commercially available can beemployed as the circuits of the echo canceler 2811, audio codec 2810,network interface 2803, etc., the teleconference module 2001 can besatisfactorily constructed using the circuit boards 2603, 2604, 2605 and2606 of the aforementioned sizes.

If the teleconference module 2001 has the dimensions of a height within150 mm, a width within 500 mm and a depth within 450 mm, it can be usedwithout hindrance in the state in which it is placed on the display unitrack 2008 or the display unit 2007 as shown in FIG. 14. In addition, itcan be housed in the rack 2008 without hindrance.

Next, FIG. 20 illustrates the situation of the assemblage of theteleconference module 2001.

As shown in the figure, the teleconference module 2001 is assembled insuch a way that a top panel 2711, a front panel 2712, a back panel 2713and the adjustable supports 2320 are attached to a body base 2710 onwhich the camera 2807 and the circuit boards 2601˜2606 are mounted.

Next, the control keyboard 2002 will be explained.

FIG. 21 shows the external appearance of the control keyboard 2002. Asshown in the figure, the control keyboard 2002 is in the shape of asector. Various keys are arranged on the upper surface of this controlkeyboard, while terminals 2910 for connecting microphones and alsoterminals for cables for connections with the teleconference module 2001are disposed on the rear surface. Besides, a built-in microphone 2920 isarranged in the front of this control keyboard.

The key arrangement on the upper surface of the control keyboard 2002 isillustrated in FIG. 22, and functions which are designated by the keyswill be listed in Tables 2 and 3 below:

                  TABLE 2                                                         ______________________________________                                        Names    Outlines of Functions                                                ______________________________________                                        START    Transmit func: dialing.                                                       Preset func: Input-acknowledging dial.                               REDIAL   Retransmitting to last called address.                               SPD DIAL Speedy dialing to registered No. by designating                               the No.                                                              MUTE     Turning off transmission speech, and transmitting                             mute.                                                                CANCEL   Deleting last input letter. (Also, ending help.)                     COM      Alternating HOOK states.                                             MENU     Registering, setting and acknowledging TEL                                    directory, operation modes, etc.                                     VIDEO    Non-com. period: Changing-over Auto/Manual                                    picture sending.                                                              Com. period: Requesting for manual picture                                    sending.                                                             MON/PIP  Monitor-displaying transmission picture (coded                                picture) on Whole screen/Minor screen.                               FREEZE   Freezing input of transmission picture.                              AUDIO SRC                                                                              Changing-over transmission speech between                                     handset input and external speech input.                             VIDEO SRC                                                                              Changing-over transmission picture between                                    accessory camera input and external video input.                     HELP     Displaying help information on function keys, etc.                   FAX      Connecting FAX and TEL circuit for                                            transmission/reception.                                              DATA     Turning ON/OFF RS232C port for data com.                                      between both terminal equipments.                                    TELE ↑                                                                           Zooming out built-in camera. (Hard)                                  WIDE ↓                                                                          Zooming in built-in camera. (Hard)                                   VOL ↑                                                                            Increasing sound volume of loudspeaker. (Hard)                       VOL ↓                                                                           Decreasing sound volume of loudspeaker. (Hard)                       ______________________________________                                    

                  TABLE 3                                                         ______________________________________                                        Names    Outlines of Functions                                                ______________________________________                                        CURSOR ↑                                                                         Spare, tilt ↑.                                                 CURSOR ↓                                                                        Spare, tilt ↓.                                                CURSOR →                                                                        Spare, pan →.                                                 CURSOR ←                                                                          Spare, pan ←.                                                   PIC Q SEL                                                                              Changing-over quality of transmission picture in 3                            stages (STD/FAST/DETAIL).                                            HS       Changing-over loudspeaker and handset.                               LOC/RMT  Changing-over LOCAL/REMOTE for panning,                                       tilting, zooming or focusing control.                                ______________________________________                                    

Typical keys will be explained with reference to FIG. 22. Numeral 2901indicates a volume control for controlling the sound volume of aloudspeaker 2104 built into the teleconference module 2001. Numeral 2902indicates keys for controlling the zooming functions of the camera 2807.Denoted by numeral 2903 are numerical and function keys which serve tocontrol the communication functions of the teleconference module 2001,and which are equivalent to those of an ISDN terminal equipment. In thisembodiment, however, the numerical keys are shared with alpha keys. Keys2904 serve to control a pan-tiller which is sometimes installed for thecamera 2807 of the teleconference module 2001. Besides, keys 2905 serveto change-over the picture qualities of pictures to-be-transmitted, akey 2906 serves to change-over the input of the built-in camera 2907 ofthe teleconference module 2001 and the input of the external camera seton, e.g., the document photographing stand 2004 as a transmissionpicture, and keys 2907 and 2908 serve to change-over transmission datafrom video or audio data to input data from the facsimile machine andsmall-sized computer connected to the teleconference module 2001,respectively. Further, indicators, such as an LED 2909 for indicatingthe closure of power supply, are provided on the upper surface of thecontrol keyboard 2002.

In the drawings, FIGS. 23(a), 23(b) and 23(c) are a front view, a planview and a bottom view, respectively, of the control keyboard 2002.FIGS. 24(a), 24(b), 24(c), 24(d), 24(e) and 24(f) are a right side viewof the control keyboard 2002, a left side view thereof, a rear viewthereof, a schematic sectional view thereof taken along line A-A' inFIG. 23(a), a schematic sectional view thereof taken along line B-B' inFIG. 23(b), and a schematic sectional view thereof taken along line C-C'in FIG. 23(b), respectively. In FIG. 24(c), numeral 2910 represents theterminals for connecting the external microphones.

FIGS. 25(a) and 25(b) show the internal construction of the controlkeyboard 2002.

As shown in FIG. 25(a), the control keyboard 2002 includes a switchingregulator 3001 by which a supply voltage fed from the teleconferencemodule 2001 is distributed to the individual parts of this controlkeyboard, key switches 3002 which constitute the various keys statedbefore, and LED's 3003. In addition, it includes a CPU 3007 whichcontrols the key switches 3002 and the LED's 3003 while performing theserial data communications with the teleconference module 2001 by theuse of data clock pulses supplied from this teleconference module. Alsoincluded are the built-in microphone 2920, the microphone jacks 2910 forconnecting the external microphones 2003, a microphone mixer 3005 formixing an input from the built-in microphone 2920 and inputs from theexternal microphones 2003, and the volume control 2901 for adjusting thelevels of audio signals transferred from the audio signal outputterminals 2818 and 2823 by the teleconference module 2001. Shown atnumeral 3006 are terminals for cables 3010 which lead to theteleconference module 2001.

As can be seen from the figures, the connections between this controlkeyboard 2002 and the teleconference module 2001 are collectivelyeffected by the single composite cable 3010. Besides, an output from themicrophone mixer 3005 is sent to the teleconference module 2001 througha transformer of 600 ohms by the use of a shielded cable 3011 which isdisposed in the composite cable 3010 as shown in FIG. 25(b).

Next, the document photographing stand 2004 will be explained.

FIG. 26 shows the external appearance of the document photographingstand 2004.

Roughly speaking, the document photographing stand 2004 is constructedof a platen 3101, a lower link 3102, an upper link 3103 and the camera3104. Besides, an LED 3105 is embedded in the central part of the platen3101, and camera controlling keys 3106 are disposed at one corner of theplaten 3101. The camera controlling keys 3106 include zooming controlkeys (wide angle/telescopic), an autofocusing function enabling key anda manual focusing controlling key for the camera 3104.

The lower link 3102 is pivotally mounted on the platen 3101, the upperlink 3103 is pivotally mounted on the lower link 3102, and the camera3104 is pivotally mounted on the upper link 3103. Thus, the camera 3104can photograph, not only a document set on the platen 3101, but alsospaces before and behind the platen 3101. Accordingly, when theblackboard 2005 is arranged behind the platen 3101 as shown in FIG. 14referred to before, characters, patterns etc. written and drawn on thisblackboard can be photographed and transmitted except during thephotographing of the document.

The LED 3105 embedded in the upper surface of the platen 3101 serves tofacilitate the positioning of the document to-be-photographed. Morespecifically, when an illuminator is provided in this manner, thecentral point of photographing can be readily grasped with transmittedlight even for a paper or the like which is placed on the platen 3101for the photographing. Herein, LED's may well be disposed at the fourcorners of a photographing region on the platen 3101 for a document ofstandard size (for example, A4-format or B5-format). Owing to thetransmitted light beams of such LED's, the desired region of a documentlarger than the standard size can be grasped and photographed moreeasily than with a conventional platen on which the four corners aremarked.

In the drawings, FIGS. 27(a), 27(b), 27(c) and 27(d) are a front view, aright side view, a plan view and a bottom view, respectively, of thedocument photographing stand 2004. FIGS. 28(a) and 28(b) are a rear viewand a left side view, respectively, of the document photographing stand2004.

In the document photographing stand 2004 according to this embodiment,as shown in FIG. 29(a), the length l of the lower link 3102 is set so asnot to exceed the length L of the platen 3101, and the length m of theupper link 3103 is set so as to be shorter than the length l of thelower link 3102. Besides, as shown in FIG. 29(b), the width N betweenboth the arms of the lower link 3102 is set greater than the width nbetween both the arms of the upper link 3103. Accordingly, as seen froma front view, a side view and a plan view depicted in FIGS. 30(a), 30(b)and 30(c), respectively, the lower link 3102 can be folded on the platen3101, and the upper link 3103 can be folded inside the lower link 3102.Thus, the document photographing stand 2004 can be carried or stored ina compact state.

Finally, the man-machine interface of the teleconference system will beexplained.

During a teleconference, the received picture of the oppositecommunicating side is usually displayed on the screen of the displayunit 2007. When the monitor/PIP key of the control keyboard 2002 statedbefore is depressed, the teleconference module 2001 presents a minorframe at the right corner of the monitor screen and displays theself-picture thereof photographed by its own camera 2807, as illustratedin FIG. 31. Further, when the monitor/PIP key is depressed in thisstate, the teleconference module 2001 displays the self-picture on thewhole monitor screen, and when the key is depressed again, the module2001 brings the screen back into the usual state and displays thepicture of the opposite communicating side on the whole monitor screen.Such a picture-in-picture display process has been detailed inconnection with the first embodiment.

In addition, the teleconference module 2001 guides operations andreports statuses by the use of the display of the display unit 2007.

FIG. 32 illustrates the situations of the operation guidance and statusreport utilizing the monitor screen.

Letter a in FIG. 32 denotes the display of the display unit 2007 at theclosure of the power supply. The current time is indicated at the leftupper corner part of the display screen of the display unit 2007.

When the start key of the control keyboard 2002 is depressed in thisstate, the monitor display is changed as shown at b in FIG. 32, and amessage for promoting a dial input is indicated. Subsequently, when thenumerals of the telephone No. of the opposite communicating side for theteleconference are input with the numerical keys of the control keyboard2002, they are successively indicated as shown at c in FIG. 32. Next,when the start key is depressed again by the operator of the controlkeyboard 2002 having acknowledged the indicated telephone No., theteleconference module 2001 establishes a channel with the ISDN totransmit the input No., and it presents a display to the effect ofcalling the opposite terminal as shown at d in FIG. 32. Then, whencommunications with the opposite terminal have begun, an elapsed timesince the beginning is indicated as shown at e in FIG. 32.

On the other hand, in a case where a reception has arrived at theteleconference module 2001 in a non-communicating period, a display tothe effect that the reception has arrived is presented together with thetelephone No. of a transmitting source as shown at f in FIG. 32.

Moreover, the teleconference module 2001 according to this embodimentoffers other various functions in a menu form.

FIG. 33 illustrates menus which are displayed on the display unit 2007.

When the menu key among the control keys is depressed at the closure ofthe power supply or during the communications, that is, in the displaystate shown at a or e in FIG. 32, the main menu shown at a in FIG. 33 isdisplayed.

In the menu a in FIG. 33, patterns are icons which are provided incorrespondence with the offered functions. The icon 3701 serves to starta telephone directory function, the icon 3702 serves to start thefunction of setting any of the various statuses of the teleconferencemodule 2001 such as the communication mode and display mode thereof, theicon 3703 serves to start the function of adjusting the time of atimepiece built into the teleconference module 2001, the icon 3705serves to start the function of handling information items (oppositecommunicating sides, telephone Nos, fees, etc.) on past communications,and the icon 3706 serves to select whether or not the time displaysshown in FIG. 32 are presented. Besides, the icon 3704 serves to end themenu. The respective icons are displayed in an arrangement correspondingto the arrangement of the numerals 1˜6 of the numerical keys of thecontrol keyboard 2002, and the depression of the key at thecorresponding position starts the function which is offered by thepertinent icon.

By way of example, when the telephone directory function is started bydepressing the numeral key "1", a menu as shown at b in FIG. 33 isdisplayed. More specifically, the same pattern as the icon havingstarted this function is indicated at the uppermost part, and the namesand telephone Nos. of the opposite communicating persons alreadyregistered are indicated in an area 3711. The user scrolls theindication within the area 3711 by designating an icon 3713 or 3714through the depression of the numerical key at the correspondingposition and then appoints the opposite communicating person whoseinformation is to be handled, by designating a select icon 3715 throughthe depression of the numerical key at the corresponding position. Anicon 3716 is one for returning to the menu picture a in FIG. 33.

Here, when the select icon 3715 is designated, a menu shown at c in FIG.33 is displayed. The patterns of the icon which has started thecorresponding function and the icon which was indicated at the uppermostpart of the parent menu of this menu are indicated at the uppermostpart, and all information items registered as relevant to the selectedcommunicating person are indicated in an area 3721. A TEL icon 3722serves to designate a transmission to the opposite communicating personindicated in the area 3721. When the numerical key corresponding to thisicon is depressed, the teleconference module 2001 calls the selectedcommunicating person in accordance with the registered information andends the menu processing steps, to shift to the display shown at d inFIG. 32. An icon 3724 in the menu c in FIG. 33 serves to alter theregistered information by way of example. More specifically, when thenumerical key corresponding to this icon is depressed, the function of,e.g., altering the registered information is indicated, and a new menucorresponding to the function is displayed. In the new menu, necessaryinput functions are similarly assigned to the keys of the controlkeyboard 2002 so as to accept the user's inputs of information. Herein,by way of example, alternatives to an input character are sequentiallychanged-over in accordance with a predetermined input key. Moreover, theconversion of inputs into Chinese characters can be realized byexpanding the function of a predetermined input key.

Meanwhile, in a case where the register icon 3702 has been designated inthe main menu a in FIG. 33, a menu shown at d in FIG. 33 is displayed.In this menu d in FIG. 33, the current statuses of the teleconferencemodule 2001 are indicated in an area 3731. The user designates anyindicated item and also designates an alternative icon 3732 inaccordance with steps similar to those of the operation of the menu b inFIG. 33, whereby the status of the designated item can be set anew toanother alternative registered beforehand.

In this regard, in a case where the teleconference module 2001 has beencalled amidst such a hierarchic menu process, a display to the effectthat a reception has arrived is presented in an area 3733.

Although, in this embodiment, the display unit 2007 has been describedas the CRT display device, it may well be a different one such as aliquid-crystal display device or a projection display device. Moreover,although this embodiment has been chiefly described as to the case ofplacing the teleconference module 2001 on the display unit 2007 or thedisplay rack 2008, the teleconference module 2001 may well be placed andused at any position where the built-in camera 2807 thereof canphotograph the user.

Incidentally, the teleconference module 2001 according to thisembodiment can similarly realize a video telephone system. By way ofexample, when this teleconference module 2001 is connected to any oftelevision receivers placed in the living rooms of most homes, the videotelephone system can be constructed. In such an application, theteleconference module of this embodiment might be named a "videotelephone module", but these modules are substantially identical.

As described above, according to the second embodiment, it is possibleto provide the teleconference module which is the single equipment beingsmall in size and easily portable and which can realize theteleconference system and the video telephone system when connected tothe existing display unit.

What is claims is:
 1. A teleconference terminal equipment for exchangingpictures and speech with an opposite communicating terminal equipmentthrough a communication circuit, comprising:a united body including:communication control means for controlling transmission and receptionof communication frames stipulated in CCITT recommendation H.221 througha digital communication channel provided by a basic interface of anISDN, each communication frame being capable of containing video data,audio data, user data and control data, multiplex/demultiplex means formultiplexing and demultiplexing the video data, audio data, user dataand control data of each of the communication frames to be transmittedby said communication control means and each of the communication framesreceived by the same, respectively, a picture codec which decodes apicture signal from said video data demultiplexed from within saidcommunication frame by said multiplex/demultiplex means and thendelivers said picture signal as an output, and which codes an inputpicture signal to-be-coded into said video data and then transfers saidvideo data to said multiplex/demultiplex means, said video data beingcoded in conformity with an algorithm stipulated in CCITT recommendationH.261, a camera which supplies said picture codec with a picked-uppicture signal as said picture signal to-be-coded, a display whichdisplays a picture indicated by said picture signal decoded by saidpicture codec, an audio codec which decodes speech data from said audiodata demultiplexed from within said communication frame by saidmultiplex/demultiplex means and then delivers the decoded speech data asan output, and which codes input speech data to-be-coded and thentransfers the coded speech data to said multiplex/demultiplex means, adigital-to-analog converter by which said decoded speech data deliveredfrom said audio codec is converted into an audio analog signal, amicrophone which supplies a picked-up audio signal, an audio switch, ananalog-to-digital converter which converts said picked-up audio signalinto picked-up audio data and supplies the picked-up audio data to saidaudio switch, a loudspeaker which emits speech based on said audioanalog signal produced by said digital-to-analog converter, and adigital audio input/output interface for connecting said audio switch toan external device which inputs and outputs audio data, said digitalaudio input/output interface supplies said audio switch with audio datafrom said external device, and supplies decoded speech data produced bysaid audio codec to said external device, said audio switch supplieseither one of said picked-up audio data or said audio data to said audiocodec as said speech data to-be-coded.
 2. A teleconference terminalequipment for exchanging pictures and speech with an oppositecommunicating terminal equipment through a communication circuit,comprisinga united body including: communication control means forcontrolling transmission and reception of communication frames through adigital communication channel according to a predetermined communicationprotocol, each communication frame being capable of containing videodata, audio data, user data and control data, multiplex/demultiplexmeans for multiplexing and demultiplexing the video data, audio data,user data and control data of each of the communication frames to betransmitted by said communication control means and each of thecommunication frames received by the same, respectively, a picture codecwhich decodes a picture signal from said video data demultiplexed fromwithin said communication frame by said multiplex/demultiplex means andthen delivers said picture signal as an output, and which codes an inputpicture signal to-be-coded into said video data and then transfers saidvideo data to said multiplex/demultiplex means, a camera which suppliessaid picture codec with a picked-up picture signal as said picturesignal to-be-coded, a display which displays a picture indicated by saidpicture signal decoded by said picture codec, an audio codec whichdecodes an analog speech signal from said audio data demultiplexed fromwithin said communication frame by said multiplex/demultiplex means andthen delivers the decoded audio signal as an output, and which codes aninput analog audio signal to-be-coded into said audio data and thentransfers said audio data to said multiplex/demultiplex means, an audioswitch, a microphone which supplies said audio switch with a picked-upanalog audio signal, a loudspeaker which emits speech based on saidanalog audio signal decoded by said audio codec, and a modular jackhaving a half-duplex interface for connecting said audio switch to anexternal facsimile machine of group 3 type recommended by CCITT (G3facsimile machine), said modular jack supplies said audio switch with aG3 facsimile transmission signal from said G3 facsimile machine anddelivers said decoded analog audio signal produced by said audio codecto said external G3 facsimile machine, said audio switch supplies eitherone of said picked-up analog audio signal or said G3 facsimiletransmission signal to said audio codec as said analog audio signalto-be-coded.
 3. A teleconference terminal equipment for exchangingpictures and speech with an opposite communicating terminal equipmentthrough a communication circuit, comprising:a united body including:communication control means for controlling transmission and receptionof communication frames through a digital communication channelaccording to a predetermined communication protocol, each communicationframe being capable of containing user data which is capable ofcontaining data from a facsimile machine of a group 3 type recommendedby CCITT (G3 facsimile data), video data, audio data, and control data,multiplex/demultiplex means for multiplexing and demultiplexing thevideo data, audio data, user data and control data of each of thecommunication frames to be transmitted by said communication controlmeans and each of the communication frames received by the same,respectively, a picture codec which decodes a picture signal from saidvideo data demultiplexed from within said communication frame by saidmultiplex/demultiplex means and then delivers said picture signal as anoutput, and which codes an input picture signal to-be-coded into saidvideo data and then transfers said video data to saidmultiplex/demultiplex means, a camera which supplies said picture codecwith a picked-up picture signal as said picture signal to-be-coded, adisplay which displays a picture indicated by said picture signaldecoded by said picture codec, an audio codec which decodes an analogspeech signal from said audio data demultiplexed from within saidcommunication frame by said multiplex/demultiplex means and thendelivers the decoded speech signal as an output, and which codes aninput analog speech signal to-be-coded into said audio data and thentransfers said audio data to said multiplex/demultiplex means, amicrophone which supplies said audio codec with a picked-up analogspeech signal as said analog speech signal to-be-coded, a loudspeakerwhich emits speech based on said analog speech signal decoded by saidaudio codec, a codec for a facsimile machine, said codec decodes G3facsimile data contained in said user data multiplexed by saidmultiplex/demultiplex means into an analog facsimile signal, and codesan analog facsimile signal to-be-coded into G3 facsimile data andsupplies said multiplex/demultiplex means with said G3 facsimile data assaid user data to be multiplexed by said multiplex/demultiplex means,and a modular jack of a half-duplex interface for connecting saidteleconference terminal equipment to a G3 facsimile machine of a group 3type recommended by CCITT (G3 facsimile machine, said modular jackreceives a G3 facsimile transmission signal from said G3 facsimilemachine, supplies said codec with said received G3 facsimiletransmission signal as said analog facsimile signal to-be-coded anddelivers the decoded analog facsimile signal produced by said codec tosaid G3 facsimile machine.
 4. A teleconference modulecomprising:communication control means for controlling transmission andreception of video data through a digital communication channel; acommunication terminal for said digital communication channel; anexternal video output terminal for an external display unit; a picturecodec which decodes a picture signal from said video data received bysaid communication control means and then outputs said picture signal tosaid external video output terminal, and which codes an input picturesignal to-be-coded into said video data and then transfers said videodata to said communication control means; a camera which photographs anexternal subject, and by which a picture signal produced byphotographing is transferred as said picture signal to-be-coded to saidpicture codec; and a box-shaped housing in which said communicationcontrol means, said picture codec and said camera are housed, saidbox-shaped housing accommodating no internal display for displaying apicture indicated by said picture signal therein; wherein said camera isarranged in a central position of said box-shaped housing with respectto a horizontal direction, so as to photograph an external subjectthrough a window provided in a central position, with respect to ahorizontal direction, of a front panel of said box-shaped housing; saidcommunication terminal and said external video output terminal areprovided on a panel of said box-shaped housing other than said frontpanel; said box-shaped housing has a size permitting said teleconferencemodule to be placed on top of the external display unit; and saidteleconference module constitutes, in combination with the externaldisplay unit, a teleconference terminal for exchanging pictures with anopposite communicating equipment through the communication channel incombination with the external display when said teleconference module isplaced on top of the external display unit, said external output videoterminal connects with the external display unit and said communicationterminal connects with the digital communication channel.
 5. Ateleconference module comprising:communication control means forcontrolling transmission and reception of video data through a digitalcommunication channel; a communication terminal for said digitalcommunication channel; an external video output terminal for an externaldisplay unit; a picture codec which decodes a picture signal from saidvideo data received by said communication control means and then outputssaid picture signal to said external video output terminal, and whichcodes an input picture signal to-be-coded into said video data and thentransfers said video data to said communication control means; a camerawhich photographs an external subject, and by which a picture signalproduced by photographing is transferred as said picture signalto-be-coded to said picture codec; an external audio input terminal foran external microphone; an external audio output terminal for anexternal loudspeaker; an audio codec which decodes a speech signal fromsaid audio data demultiplexes by said multiplex/demultiplex means andthen outputs said speech signal to said external audio output terminal,and by which an input speech signal to-be-coded input from said externalaudio input terminal is coded into speech data; and a box-shaped housingin which said communication control means, said multiplex/demultiplexmeans, said picture codec, said camera and said audio codec are housed,said box-shaped housing accompanying no internal display for displayinga picture represented by said picture signal therein; wherein saidcamera is arranged in a central position of said box-shaped housing withrespect to a horizontal direction so as to photograph an externalsubject through a window provided in a central position of a front panelof said box-shaped housing with respect to a horizontal direction; saidcommunication terminal, said external video output terminal, saidexternal audio input terminal and said external audio output terminalare provided on a panel of said box-shaped housing other than said frontpanel; said box-shaped housing has a size permitting said teleconferencemodule to be placed on top of the external display unit; and saidteleconference module constitutes, in combination with the externaldisplay unit, external microphone and external loudspeaker, ateleconference terminal for exchanging pictures with an oppositecommunicating equipment through the communication channel, incombination with the external display when said teleconference module isplaced on top of the external display unit, said external output videoterminal connects with the external display unit, external audio inputterminal connects with the external microphone, said external audiooutput terminal connects with the external loudspeaker and saidcommunication terminal connects with the digital communication channel.6. A teleconference module as defined in claim 4, wherein saidcommunication terminal and said external video output terminal areprovided on the panel of said box-shaped housing other than said frontpanel.
 7. A teleconference module as defined in claim 5, wherein saidcommunication terminal, said external video output terminal, saidexternal audio input terminal and said external audio output terminalare provided on the panel of said box-shaped housing other than saidfront panel.
 8. A teleconference module as defined in claim 6, whichcomprises an external data input/output terminal;wherein saidcommunication control means controls transmission of the user data inputfrom the external data input/output terminal through a digitalcommunication channel, and outputting the user data received from saidcommunication channel to said external data input/output terminal, andsaid external data input/output terminal is provided on the panel ofsaid box-shaped housing other than said front panel.
 9. A teleconferencemodule as defined in claim 7, which comprises an external datainput/output terminal;wherein said communication control means controlstransmission of the user data input from the external data input/outputterminal through a digital communication channel, reception of the userdata through a digital communication channel, and outputting the userdata received from said communication channel to said external datainput/output terminal, and said external data input/output terminal isprovided on the panel of said box-shaped housing other than said frontpanel.